I'm in the HD van camp. Express 3500 with 6.0 and optionalaxle ratios can pull that, but finding one with the 6.6 Duramax would be better. Express seats still clamp into slots in the floor, making it easy to configure for passengers vs cargo.
E-350 van (no longer made) you would have to find the 6.8 V-10 with 4.10 axle, or take your chances on a 6.0 Powerstroke, which tends to be more reliable in the van because it was derated for that application. 2008 and newer get a better front suspension and better brakes, but the interior upgrade put much heavier seats into above-floor mountng brackets, so it is much harder to remove and replace seats, and 15-20 minutes work to pull the brackets out and plug holes to get a flat floor.
